Capacitors have many applications in integrated circuitry. For instance, dynamic random access memory (DRAM) unit cells may comprise a capacitor in combination with a transistor. Charge stored on the capacitors of the DRAM unit cells may correspond to memory bits.
A continuing goal of integrated circuit fabrication is to decrease the area consumed by individual circuit components, and to thereby increase the density of components that may be provided over a single chip (in other words, to increase the scale of integration). Thus, there is a continuing goal to miniaturize the various components utilized in integrated circuitry.
A problem that may occur during the miniaturization of capacitors is that smaller capacitors may have correspondingly less capacitance than larger capacitors. The amount of charge that may be stored on individual capacitors may be proportional to capacitance, and there may be a minimum capacitance per cell that is required for reliable memory operation. Accordingly, it is often not practical to simply scale-down the size of existing capacitors to achieve capacitors suitable for future generations of integrated circuitry. Rather, the miniaturized capacitors will not meet desired performance parameters unless new materials are developed which improve capacitance within the miniaturized capacitors.
One method of increasing capacitance is to decrease the thickness of dielectrics utilized in the capacitors. However, current leakage becomes problematic with decreasing dielectric thickness.
It would be desirable to develop improved integrated circuit capacitors having desired capacitance, and not having problematic leakage.